Answer: A. They were all hybrids
Explanation:
Hybrid is another term for heterozygous.
When an individual is heterozygous for a trait, they contain one dominant allele (A) and one recessive allele (a)
In Mendel's experiment, he crossed two pure breeding (homozygous) pea plants one having the genotype AA and the other aa
If you do a punnet square, the offspring (F1 generation) would all have the genotypes Aa thus being hybrids or heterozygotes
